Conveyor systems wherein a frictional roller engages a flexible element in driving/driven relationship are well known. Typically, the flexible element is in the form of a belt or rope. Most frequently, the frictional roller will be formed from a metallic substance or an elastomeric substance having elevated abrasion resistance properties.
Often such conveyor systems find application in apparatus wherein the frictional roller is driven and imparts motion to the flexible element as the flexible element frictionally engages the roller. For example, in a long conveyor system, one or more ropes or cables may pass around a driven drum and support a conveying belt. In a lifting apparatus, typically the object being lifted is carried by a rope passing over a number of pulleys and engaging a driven drum or winch. In such applications, the ropes generally are formed from a metallic substance such as steel and are more frequently termed as cables. Typically, such cables or ropes are possessed of significant magnetic properties.
In such conveying systems, the frictional roller and the cable or rope establish a driving interrelationship resulting from frictional engagement between the frictional roller and the rope. Such frictional engagement typically causes wear both to the rope and to the frictional roller. The frictional wear typically necessitates more frequent replacement of the ropes and/or the frictional roller resulting in an elevated maintenance expense. Where the tension under which a rope or a cable in such a system is maintained, is increased in order to reduce slippage at the point of frictional engagement between the rope and the frictional roller, generally the rope or cable suffers a reduced service life.
A conveying device wherein an enhanced driving contact can be maintained between the flexible element and the frictional roller while relieving the necessity for maintaining the flexible element under a substantially elevated tension, could find wide utility in the manufacture of conveying systems.